A year ago I tried asking, but I didn't get definitive answer. So I will try again now.
I want to spend ALL the balance from a channel via the lightning network. Normally the protocol won't allow that as it requires a local reserve. But if the channel is simultaneously closed this is no longer a problem. Does the lightning network support such a transaction? Spend all and close simultaneously.
Spend all and close simultaneously does not exist AFIAK. But nowadays a lot of implementations support the option for 0 reserve channels. We just added it to LDK!
then question becomes "can we re-negotiate the reserve to 0 along with the preimage of spending the local balance"?
in this case it would need to happen simultaneously somehow.
Exactly. Leaving 0 reserve has negative impact on your channel partner, but spending and closing doesn't.
I don't really see the use case you're looking for here
I do 😎
source
https://twiiit.com/ajtowns/status/2044494089048190992